Percutaneous puncture treatment, in which a needle is guided to the affected part, is a typical example of minimally invasive treatment that is commonly performed. Examples of puncture treatments include ablation treatment in which a tumor or cancer cells are burned with radio waves and cryotherapy in which a tumor or cancer cells are frozen by using, for example, a freezing device or cooling gas. Puncture biopsy has also been commonly performed in pathological diagnosis based on tissue sampling.
In the medical environment, it is necessary to position a needle or multiple needles precisely inside tissue or a specific organ for accurate diagnosis or minimal invasive therapy. Biopsy, ablation, cryotherapy, aspiration and drug delivery are examples that require high precision needle placement and many of these treatments require the use of multiple needles in a treatment. Prior to a percutaneous incision, a target area of interest (e.g., tumor, nodule, etc.) is confirmed by means of non-invasive imaging with MRI, ultrasound or other imaging modality. Once the target area of interest is positively determined, the clinician decides an entry point, inserting direction and depth to be reached by the needle. This process often requires a lengthy trial and error routine, which can be deleterious to the patient. Accordingly, in the last few decades there has been an increased interest in the development of needle guiding systems that can improve accuracy of needle positioning, minimize patient discomfort, and shorten time of operation.
To accurately position a needle with respect to a target, such as a tumor, in puncture treatment, an X-ray CT unit, an MRI unit, etc., for acquiring medical images is used as a visualization unit for visualizing the needle. In puncture treatment in which such a modality is used as a visualization unit, it is often difficult to position the needle with respect to the target by a single puncturing process. Thus, the needle is generally guided to the target by acquiring medical images multiple times and correcting the insertion trajectory little by little in accordance with information from the acquired images. Accordingly, to reduce the operation time and burden on patients as well as patient's exposure to imaging radiation, various needle positioning apparatuses for positioning the needle to the target to provide a reduction in the number of times of corrections of the trajectory have been developed.
For example, US2006/0229641, entitled “Guidance and Insertion System”, discloses a needle positioning apparatus including a remote-center-of-motion (RCM) mechanism. According to US2006/0229641, an insertion direction is determined by driving motors, and puncturing is performed by a motor. Then, a motor is driven so as to release the needle from the needle positioning apparatus. In the case where multiple-needle puncture is performed by using this apparatus, the needle is set between a drive roller and a passive roller. If a second or additional needle is needed, the previously inserted needle is clamped between the drive roller and the passive roller and will interfere with the second or additional needle being inserted. Therefore, in multiple-needle puncture, positioning of the subsequently inserted needles cannot be performed with this apparatus.
US2006/0149147, entitled “Remotely Held Needle Guide for CT Fluoroscopy”, relates to a needle positioning apparatus including a vertical articulated arm, and discloses a mechanism for releasing a needle from a needle holder by using a grip. When multiple-needle puncture is performed by using this guide apparatus, a needle can be released from a needle holder by controlling a gripping area. However, for this to occur, a main body needs to be retracted before the next insertion. More specifically, the main body needs to be carefully retracted so that the needle holder does not interfere with the needle. Thus, the vertical articulated arm is required to make a complex movement to retract the main body.
As another example of a needle positioning apparatus, Song S, Tokuda J, Tuncali K, Yamada A, Torabi M, Hata N., “Design Evaluation of a Double Ring RCM Mechanism for Robotic Needle Guidance in MRI-guided Liver Interventions”, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Nov. 3-7, 2013, discloses a double-ring-type needle positioning apparatus, which is a two-degree-of-freedom RCM mechanism. However, an apparatus for multiple needle placements is not provided in this apparatus.
Thus, there is need for needle positioning apparatus that are suitable for, for example, minimally invasive puncture treatment and can, for example, assist in providing a more exact location of needle placement, reduce the time required to place the needle, reduce the number of punctures during a procedure, reduce the number of images required to place the needle(s), and/or aid in the placement of multiple needles during a procedure.